Toothbrushes are big business, including eco-friendly ones.
Apparently Humble Co. has sold more than 35 million of their bamboo toothbrushes worldwide, which is definitely something. I'm not sure what the total number of brushes bought worldwide is though, some huge number I guess.
For the record, it's made from sustainably grown bamboo and the packaging is compostable, but the bristles are nylon.